5-1 (8.10.16) Flashcards
define cytoskeleton
- def
- euk or pro
protein framework extending thru cytosol
euk
order lengths (short to long)
short: actin
intermediate filament
long: microtubule
what protein cross links IMF, MT, A
P-LECTIN
”” binds to actin monomers to prevent assembly until filaments are needed
”” proteins (AND nickname) promote assembly
monomer-sequestering protein
nucleating proteins
ARP complexes
myosin # occurs in all cells and has one head domain and tail
1
REL between myosin and actin
Myosin moves along actin TOWARD plus end.
myosin # for muscle
2
where else myosin 2 does its contracting thin
contractile bundles and ring
what causes contraction of sarcomere
movement of myosin
motor molecule, before it can walk, needs to
have its shape changed via hydrolysis of ATP
K molecules (FC for name) move to +/- end of MT
what moves to OPP direction
KI-NESIN
+
DY-NEIN moves to MINUS end
REL between K and myosin #
REL: similar structure
2
K and D are motor molecules on what kind of (MT/actin/IMF)
MT
what’s the dif bt D and K in terms of structure
K is taller
head/tail of motor molecule binds to cargo
tail
read: each step of K or D requires hydrolysis of ATP
-
cilia’s beat does what
moves liquid over epithelia
function of “” and “” spokes
converts “” “” into “” “”
Nexin; radial
convert doublet sliding into ciliary bending
describe sliding doublet model
something changes about dynein arm -> DOUBLET walks -> nexin and radial spokes prevent from continuing
describe primary cilia (structure, 2 things)
LACK dynein arms
don’t move
describe primary cilia function
- imp in development
- in KIDNEY, are flow sensors
dif bt taxol and VV
taxol binds to MT
VV binds to dimer
listeria is acquired via (what health behavior)
food poisoning
mec of listeria
listeria doesn’t have its own actin BUT it hijacks the host cell’s ARP complex for actin polymerization and uses this for movement
read: immotile cilia syndrome may have situs inversus
-
term for on belly
prone
if you are moving up and down the body (head to toe direction), what TERM indicates toward head
if you are moving from belly button to back, what TERM indicates the back
superior
dorsal
how do you make a sagittal cut
person is laying on his stomach
you take a knife and chop him right down his spine, separating the left and right sides of him
above the diaphragm is what
below
above - thorax
below - abdomen
name of the model of membrane
fluid mosaic
list transport mec across mem (3)
1) diffusion
2) diffusion thru ion channels
3) carrier mediated
- facilitated diffusion
- coupled carrier
- active (pumps)
diffusion is only useful physiologically over what
very short distance
rate of diffusion is proportional to
concentration gradient
diffusion coefficient
diffusion rate in solution can be described by what law
Fick’s First law
read: direction of flux is from higher to lower conc means + membrane flux
-
diffusion of a charged molecule depnds on [ ] AND
electric field effects
ex of things that cross via diffusion (4)
02
benzene
urea
C02
define osmosis
net flux of water across a semi permeable membrane from area of low solute [ ] to area of high solute [ ]
osmolarity vs osmolality
rity = # moles/L lity = # moles/kg
define osmotic pressure
pressure req to prevent osmotic FLOW Of water
II = RT(ic)
is eq for
eq is called
where do you get the osmolarity in eq
osmotic pressure
van’t Hoff relation
via IC
steady state cell V depends on
[ ] of impermeant solutes
flow of ions thru channel is driven by what
electrochemical gradient ( [ ] and membrane voltage)
which is faster: ion transport or carrier
ion
list the classes of ion channels
-light gated is…
1) ligand gated
2) voltage gated
3) stretch gated/mechano-sensitive
4) temp gated
5) light gated (not found in mammals)
stretch gated channels exist are involved in what kinds of sensation
auditory
transport by ion channels is (active/passive)
passive
facilitated diffusion via carriers ( ) depend directly on ATP
does NOT
co transport ex (2)
Na and glucose (read: Na is going DOWN gradient while glucose goes UP gradient)
Na and amino acids
carriers that rely on an ion gradient controlled by a pump are called
secondary active transport
read: transport of glucose and AA by Na coupled carriers ARE examples
define exchange carriers
ex
transport two in OPP direction
Na/Ca exchanger (Na into, Ca OUT against gradient)
what’s the key pt about active transport
carrier
fueled by ATP
Na/K pump maintains what conditions (in and out of cell)
intra: high K, low Na
someone wt diabetes -> excess glucose show up in urine bc ??
glucose carriers in kidneys are saturated
cannot transport ALL glucose into bloodstream
leaky epithelia transport what
tight epithelia does what
leaky = isosmotic fluid
tight = maintain large osmotic gradient
*renal collecting duct or stomach
toxins typically attack what
ion channels
dif bt ion selectivity and gating
which channel is this applicable for
s = which ions they transport
g = what causes them to open and close
ION channel
